Set defaults for swift_vars and swift_proxy_vars

Use the defaults file to set the 'swift_vars' and 'swift_proxy_vars'
variables instead of set_fact tasks.

Change-Id: I52636950652180c4192ad7596dc96c397a7c78f9

defaults/main.yml

@@ -236,6 +236,8 @@ swift_service_in_ldap: false
 
 # Basic swift configuration for the cluster
 swift: {}
+swift_vars: {}
+swift_proxy_vars: {}
 
 # Example basic swift configuration for the cluster
 # swift:

tasks/main.yml

@@ -31,22 +31,6 @@
   tags:
     - swift-config
 
-# We need swift_vars to exist for the "swift_vars.* is defined check" to work
-- name: "Set swift_vars if undefined"
-  set_fact:
-    swift_vars: "{}"
-  when: swift_vars is not defined
-  tags:
-    - always
-
-# We need swift_proxy_vars to exist for the "swift_proxy_vars.* is defined check" to work
-- name: "Set swift_proxy_vars if undefined"
-  set_fact:
-    swift_proxy_vars: "{}"
-  when: swift_proxy_vars is not defined
-  tags:
-    - always
-
 - include: swift_pre_install.yml
   when:
     - swift_do_setup | bool